Kleeja/includes/captcha.php

<?php
/**
*
* @package Kleeja
* @copyright (c) 2007 Kleeja.net
* @license ./docs/license.txt
*
*/

// Fix bug with path of font When using versions of the GD library lower than 2.0.18
if (function_exists('putenv'))
{
    @putenv('GDFONTPATH=' . realpath('.'));
}
elseif (function_exists('ini_set'))
{
    @ini_set('GDFONTPATH', realpath('.'));
}


// When any body request this file , he will see an image ..
kleeja_cpatcha_image();

exit();

//
//this function will just make an image
//source : http://webcheatsheet.com/php/create_captcha_protection.php
//
function kleeja_cpatcha_image()
{
    //Let's generate a totally random string using md5
    $md5_hash = md5(rand(0, 999)); 

    //I think the bad things in captcha is two things, O and 0 , so let's remove zero.
    $security_code = str_replace('0', '', $md5_hash);

    //We don't need a 32 character long string so we trim it down to 5 
    $security_code = substr($security_code, 15, 4);

    //Set the session to store the security code
    $_SESSION['klj_sec_code'] = $security_code;

    //Set the image width and height
    $width  = 150;
    $height = 25; 

    //Generate a random number of lines to make the image dirty
    $lines  = rand(3, 5);

    //Create the image resource 
    $image = imagecreate($width, $height);  

    //We are making three colors, white, black and gray
    $white = imagecolorallocate($image, 255, 255, 255);
    $black = imagecolorallocate($image, rand(0, 100), 0, rand(0, 50));
    $grey  = imagecolorallocate($image, 204, 204, 204);

    //Make the background black 
    imagefill($image, 0, 0, $black); 

    //options
    $x     = 10;
    $y     = 14;
    $angle = rand(-7, -10);

    //Add randomly generated string in white to the image
    if (function_exists('imagettftext'))
    {
        //
        // We figure a bug that happens when you add font name without './' before it .. 
        // he search in the Linux fonts cache , but when you add './' he will know it's our font.
        //
        imagettftext($image, 16, $angle, rand(50, $x), $y+rand(1, 3), $white, dirname(__FILE__) . '/arial.ttf', $security_code);
        //imagettftext ($image, 7, 0, $width-30, $height-4, $white,'./arial.ttf', 'Kleeja');
    }
    else
    {
        imagestring($image, imageloadfont(dirname(__FILE__) . '/arial.gdf'), $x+rand(10, 15), $y-rand(10, 15), $security_code, $white);
        //imagestring ($image, 1, $width-35, $height-10, 'Kleeja', ImageColorAllocate($image, 200, 200, 200));
    }

    //Throw in some lines to make it a little bit harder for any bots to break 
    imagerectangle($image, 0, 0, $width-1, $height-1, $grey);

    for ($i=0; $i<$lines; $i++)
    {
        imageline($image, rand(0, $width), rand(0, $height), rand(0, $width), rand(0, $height), $grey);
    }


    //Tell the browser what kind of file is come in and prevent client side caching
    header('Expires: Wed, 1 Jan 1997 00:00:00 GMT');
    header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
    header('Cache-Control: no-store, no-cache, must-revalidate');
    header('Cache-Control: post-check=0, pre-check=0', false);
    header('Pragma: no-cache');
    header('Content-Type: image/png');

    //Output the newly created image in jpeg format 
    imagepng($image);

    //Free up resources
    // imagedestroy() has no effect since PHP 8.0
    // Only call it for PHP < 8.0 where it actually frees memory
    if (PHP_VERSION_ID < 80000)
    {
        imagedestroy($image);
    }
}

//<--- EOF